Enzymatic hydrolysis and fermentation of palm kernel press cake for production of bioethanol

Published Date
Enzyme and Microbial Technology
5 March 2010, Vol.46(3):177–184, doi:10.1016/j.enzmictec.2009.10.012

• Author 

• José María Cerveró ^a
• Pernille Anastasia Skovgaard ^b
• Claus Felby ^b
• Hanne Risbjerg Sørensen ^c,1
• Henning Jørgensen ^b,,

• aDepartment of Chemical Engineering and Environmental Technology, University of Oviedo, C/Julián Clavería, 8, 33071, Oviedo, Spain
• bDanish Centre for Forest, Landscape and Planning, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark
• cNovozymes A/S, Krogshøjvej 36, DK-2880 Bagsværd, Denmark

Received 29 June 2009. Revised 25 September 2009. Accepted 27 October 2009. Available online 6 November 2009.

Abstract

Palm kernel press cake (PKC) is a residue of palm oil extraction, which was found to contain 48.5% of total carbohydrates of which 35.2% was mannan. The present study examines enzymatic hydrolysis of polysaccharides from the cell-wall material present in PKC to obtain monosaccharides that can be substrate in various fermentation processes such as ethanol production. The requirements for pretreatment were investigated and it was found that mannan in PKC was readily hydrolysed without any pretreatment. Several enzyme preparations were tested and Mannaway 25L was found as the best for releasing mannose, and Gammanase 1.0L worked well in degrading cellulose and mannose. Binary mixtures of enzymes were tested to increase the conversion, and 1:1 mixture of Mannaway 25L and Gammanase 1.0L showed good synergistic effect releasing 30% more mannose than the sum obtained using these enzymes individually. Using an enzyme loading of 2.3 mg protein/g PKC resulted in 63% of mannan in PKC being hydrolysed to mannose in 24 h, and in 96 h a total of 365 g mannose and glucose could be produced per kg PKC. Finally, PKC was hydrolysed and fermented using Saccharomyces cerevisiae with an ethanol yield of 125 g/kg PKC.

Keywords

Bioethanol

Palm kernel press cake

Mannan

Saccharomyces cerevisiae

---

 Table 1

Table 1.

 Table 2

Table 2.

 Table 3

Table 3.

 Table 4

Table 4.

 Table 5

Table 5.

Fig. 1.

Fig. 2.

• ⁎ 
  Corresponding author. Tel.: +45 3533 1704; fax: +45 3533 1508.

Copyright © 2009 Elsevier Inc. All rights reserved.

For further details log on website:
http://www.sciencedirect.com/science/article/pii/S014102290900249X